A pair of environmental groups notified federal officials Wednesday that they plan to sue over the government's failure to protect habitat for the endangered Florida panther. In January, the Sierra Club and the Conservancy of Southwest Florida officially petitioned the U.S. Fish and Wildlife Services to declare a large swath of South Florida to be critical habitat for the panther, and several congress members sent a letter to President Obama urging quick action. Eleven months later, the agency still has taken no action, so the groups notified agency leaders they plan to sue. Agency spokesman Ken Warren would not comment on the subject of a lawsuit. As for the petition itself, he said, they were continuing "to carefully weigh the merits of designating critical habitat." A previous request for critical habitat for the panther, filed in 2003, drew a response from the agency five years later saying no.